(1) Field of the Invention
The present invention relates to damping support structures for preventing horizontal and vertical vibrations of manufacturing apparatus. Such a support structure is installed in an LSI manufacturing plant, a laser appliance manufacturing plant or the like to support apparatus for manufacturing ultra-high precision devices such as semiconductors and printed circuit boards. The support structure absorbs vibrations due to earthquakes or microvibrations due to running vehicles through a floor or other base structure, thereby preventing vibrations of a table supporting the manufacturing apparatus.
(2) Description of the Prior Art
At the LSI manufacturing plant, laser appliance manufacturing plant and the like, it is necessary to suppress microvibrations since even microvibrations result in defective products. A conventional damping support structure includes spring elements such as laminated rubber layers and air springs arranged at four peripheral positions between a table on which a manufacturing apparatus is mounted and the floor or other base structure. These spring elements elastically support the apparatus table, with the air springs in particular efficiently absorbing microvibrations, while mitigating shocks due to vibrations. This damping support structure further includes actuators such as linear motors arranged between the apparatus table and the base structure, and at different positions to the spring elements. Controls are provided through the actuators in response to vibrations of the apparatus table, thereby to check the apparatus table vibrations.
In the conventional support structure, however, the spring elements for mitigating shocks due to vibrations and the actuators for applying the controls comprise separate components disposed at different positions. This construction requires many troublesome steps in assembling the apparatus table and the support structure together. Further, spaces must be secured between the apparatus table and the base structure for accommodating those components, which results in the disadvantage of the entire damping structure becoming large.